In 2008, the CDC expanded the indications for influenza vaccination to encompass children ages 6 months through 18 years, dramatically increasing the number of eligible children. Innovative strategies to increase vaccination rates are needed due to the increased workload and to the fact that adolescents make fewer health supervision visits. During the first year, we will identify and develop strategies to increase influenza vaccination of children in practice settings, using the Diffusion of Innovation Theory. Identification will occur by a literature review and by focus groups of Allegheny County Immunization Coalition members and parents. Then, we will develop and formatively evaluate new, electronic, mass media messages targeting parents and teens, using graphic expertise in our Center for Instructional Development and local media. Next, we will develop a package of strategies to increase rates including a toolkit, standing orders, express vaccination clinics, workflow redesign to assess vaccination status during vital signs, early start to the vaccination season in August using live attenuated influenza vaccine, and autodialed reminders. We will also work with primary care practices to educate clinicians, to enhance electronic record keeping by reviewing documentation and by collaborating with Pennsylvania's Statewide Immunization Information System (PA-SIIS). We will conduct a pilot test of some of the proposed interventions. To address Aim 2, in the second year, we will conduct a stratified, randomized cluster trial of 20 diverse practices to compare vaccination rates in intervention and control sites. Intervention sites will use a package of newly developed and evidence-based techniques that will be tailored to their practice structure and culture. Usual care practices will not receive such assistance. Two diverse practice-based research networks will be the focus of the study. We will evaluate the success of the intervention using a mixed methods approach, including qualitative (e.g., focus groups), process, and quantitative measures. As the patients are clustered in clinics, hierarchical linear modeling will be conducted and will include the fidelity of implementation of the intervention and practice factors associated with vaccination. Our multidisciplinary team has experience in practice-based research on barriers and facilitators to vaccination and in conducting trials. We propose to disseminate the toolkit and intervention materials on the web. PUBLIC HEALTH RELEVANCE: New recommendations by the Advisory Committee for Immunization Practices to vaccinate all children ages 6 months through 18 years against influenza will require innovative strategies to increase vaccination rates among groups with previously low vaccine uptake. This project will use a variety of methods to identify and develop a package of interventions to increase influenza vaccination rates among children. These strategies will be tested in a stratified random cluster trial of primary care practices.